How can Nigerians be protected from the annual floods?

Nigerians are facing at least three months of battling against heavy rains that could lead to deadly, destructive flooding.
At the beginning of July, the government warned that 30 of the country's 36 states could be at risk.
Already, 16 states, including the commercial hub Lagos, have been badly affected.
Five years ago, the worst flooding in more than 40 years in Nigeria claimed 431 lives and displaced nearly two million people, according to the country's National Emergency Management Agency (Nema).